Passenger seat, passenger seat leg module and method

ABSTRACT

A passenger seat which includes a seat bottom chassis assembled from a plurality of leg modules attached to fixed, spaced-apart attachment points on a supporting surface, and a plurality of beam elements for being carried by the leg modules. A plurality of clamp joints are positioned on a first side of the leg modules in a first laterally-offset relation thereto in a first spaced-apart relation to the attachment points of the supporting surface and for receiving the plurality of beam elements for defining a ladder frame assembly having a first specified width and seat spacing. The plurality of clamp joints are removable from the first side of the leg modules can positioned on a second, opposite side of the leg modules in a second laterally-offset relation for defining a ladder frame assembly having a second specified width and seat spacing while the plurality of leg modules maintain the same position relative to each other and thus to the fixed, spaced apart attachment points whereby the location of the seats may be altered while using the same beam elements.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

This invention relates to a passenger seat such as used on an aircraft,a leg module for a passenger seat, and a method of mounting a passengerseat to attachment points on a supporting surface, such as the deck ofan aircraft fuselage.

Passenger seat frames are constructed from modular sets of componentsdesigned to be lightweight and conformable to various aircraft cabinconditions. The lower seat chassis is constructed of leg modules. A legmodule includes a front leg, a diagonal leg tie and a back leg.

The upper seat chassis is constructed of section assembly modules. Theleg modules and section assembly modules are assembled by attachment tolateral tubular beam elements to form a ladder frame assembly. A seatbottom and a seat back are mounted to the ladder frame assembly to formthe passenger seat. The seat back typically includes a recline unitwhich allows the seat back to be moved between relatively upright andreclined positions for passenger comfort and ingress/egressrequirements. The location of the section assembly modules is controlledby the aircraft fuselage lines and statutory aisle requirements. Thesection modules carry pivots for both sides of the seat back and anadditional pivot on one side to carry the reaction loads of the reclineunit of the seat back.

The location of the leg modules is controlled by the position of theaircraft floor tracks which extend along the length of the fuselage, andto which the seats are affixed by track fittings carried on the bottomof the leg module. Presently, aircraft passenger seats required threedifferent leg module designs to accommodate the seat spacingrequirements while fitting into the tract fittings.

The present invention permits a single leg module to be used for allseat spacing requirements.

SUMMARY OF THE INVENTION

Therefore, it is an object of the invention to provide a passenger seatwhich includes a leg module that can be used in different spacingconfigurations.

It is another object of the invention to provide a passenger seat whichincludes a detachable joint clamp that permits a single leg module to beused in different spacing configurations.

It is another object of the invention to provide a passenger seat legmodule that can be used in different spacing configurations.

It is another object of the invention to provide a passenger seat legmodule which includes a detachable joint clamp that permits a single legmodule to be used in different spacing configurations.

It is another object of the invention to provide a method ofconstructing a passenger seat using a single type of leg module.

These and other objects of the present invention are achieved in thepreferred embodiments disclosed below by providing a passenger seatwhich includes a seat bottom chassis assembled from a plurality of legmodules, the leg modules for being attached to fixed, spaced-apartattachment points on a supporting surface, and a plurality of beamelements for being carried by the leg modules. A plurality of clampjoints are positioned on a first side of the leg modules in a firstlaterally-offset relation thereto in a first spaced-apart relation tothe attachment points of the supporting surface and for receiving theplurality of beam elements for defining a ladder frame assembly having afirst specified width and seat spacing. The plurality of clamp jointsare removable from the first side of the leg modules can positioned on asecond, opposite side of the leg modules in a second relation theretofor defining a ladder frame assembly having a second specified width andseat spacing while the plurality of leg modules maintain the sameposition relative to each other and thus to the fixed, spaced apartattachment points whereby the location of the seats may be altered whileusing the same beam elements.

According to one preferred embodiment of the invention, the passengerseat includes a seat back recline assembly, comprising a plurality ofseat section assembly modules carried by the leg modules, and a seatback unit pivotally-mounted between two of the section assembly modulesfor permitting the angle of the seat back relative to the seat bottomchassis to be varied as desired by the passenger, a recline unit forcontrolling movement of the seat back and locking the seat back in adesired recline position.

According to another preferred embodiment of the invention, each of theleg modules comprises a rear foot block and floor tie assembly, a frontleg, and a diagonal leg tie connecting the rear foot block and the frontleg. A first one of the plurality of clamp joints is connected inlaterally-offset relation to one side of the diagonal leg tieintermediate the rear foot block and the front leg, and a second one ofthe plurality of clamp joints is connected in laterally-offset relationto one side of the front leg.

According to yet another preferred embodiment of the invention, theclamp joint comprises an attachment element for being attached to theleg module and an annular collar element for receiving a beamtherethrough.

According to yet another preferred embodiment of the invention, theclamp joint attachment element includes holes therein for receivingattachment bolts therethrough and through mating holes in the legmodule.

According to yet another preferred embodiment of the invention, theclamp joint collar includes an axially-extending split therein forallowing the collar to be spread sufficiently to receive the beamtherethrough, and a threaded fastener adjustably connecting the collaron opposite sides of the split for permitting the collar to be tightenedlocking the beam in place within the collar in a predetermined positionand loosened for permitting the beam to the removed from or shiftedaxially within the collar.

According to yet another preferred embodiment of the invention, thepassenger seat includes first and second spaced-apart leg modules. Theclamp joints of the first leg module are positioned on a left sidethereof; and the clamp joints of the second leg module are positioned ona right side thereof.

According to yet another preferred embodiment of the invention, thepassenger seat includes first and second spaced-apart leg moduleswherein the clamp joints of the first leg module are positioned on aright side thereof, and the clamp joints of the second leg module arepositioned on a right side thereof.

According to yet another preferred embodiment of the invention, thepassenger seat includes first and second spaced-apart leg moduleswherein the clamp joints of the first leg module are positioned on aleft side thereof, the clamp joints of the second leg module arepositioned on a left side thereof.

According to yet another preferred embodiment of the invention, apassenger seat leg module is provided, and comprises a rear foot blockand floor tie assembly, a front leg, a diagonal leg tie connecting therear foot block and the front leg, and a first clamp joint for beingconnected in laterally-offset relation to a selected one of a left orright side of the diagonal leg tie intermediate the rear foot block andthe front leg for receiving a beam therethrough. A second clamp joint isprovided for being connected in laterally-offset relation to a selectedone of a left or right side of the front leg for receiving a beamtherethrough.

An embodiment of the method of mounting a passenger seat to attachmentpoints on a supporting surface comprises the steps of providing a seatbottom chassis including a plurality of leg modules, the leg modules forbeing attached to fixed, spaced-apart attachment points on a supportingsurface, a plurality of beam elements carried by leg modules, and aplurality of clamp joints. A clamp joint is attached to each of theplurality of leg modules for clamping the plurality of leg modulestogether in spaced-apart relation to each other, each the clamp jointhaving a hole therethrough for receiving a beam element. The pluralityof beam elements extend through an opening in the clamp joints fordefining a ladder frame assembly having a predetermined width and seatspacing.

According to yet another preferred embodiment of the invention, themethod includes the steps of removing the beams from the clamp joints,removing the clamp joints from one side of the leg modules and attachingthe clamp joints to an opposite side of the leg modules, and extendingthe plurality of beam elements through respective openings in the clampjoints to define a ladder frame assembly having a second specified widthand seat spacing.

According to yet another preferred embodiment of the invention, themethod includes the steps of positioning the clamp joints of a first legmodule on a left side thereof, and positioning the clamp joints of asecond leg module on a right side thereof.

According to yet another preferred embodiment of the invention, themethod includes the steps of positioning the clamp joints of a first legmodule on a right side thereof, and positioning the clamp joints of asecond leg module on a right side thereof.

According to yet another preferred embodiment of the invention, themethod includes the steps of positioning the clamp joints of a first legmodule on a left side thereof, and positioning the clamp joints of asecond leg module on a left side thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter that is regarded as the invention may be bestunderstood by reference to the following description taken inconjunction with the accompanying drawing figures in which:

FIG. 1 is a schematic perspective view of an aircraft seat setconstructed in accordance with the present invention;

FIG. 2 is a schematic perspective view of the seat set of FIG. 1,showing the rear of the seat set;

FIG. 3 is a side view of the seat of FIG. 1;

FIG. 4 is a schematic perspective view of the internal structure of theseat set depicted in FIG. 1;

FIG. 5 is a side view of the internal seat structure of shown in FIG. 4;

FIG. 6 is an exploded perspective view of a seat back recline lockingassembly constructed in accordance with the present invention;

FIG. 7 is an exploded perspective view of a seat back recline lockingassembly along with a portion of a seat set internal structure;

FIG. 8 is an exploded perspective view of a leg module assembly;

FIG. 9 is a perspective view of a first arrangement of a ladder frameassembly;

FIG. 10 is a perspective view of a second arrangement of a ladder frameassembly;

FIG. 11 is a perspective view of a third arrangement of a ladder frameassembly;

FIG. 12 is an exploded perspective view of a breakover assemblyconstructed in accordance with the present invention;

FIG. 13 is another exploded perspective view of the breakover assemblyof FIG. 12;

FIG. 13A is a side view of a breakover assembly in the upright position;

FIG. 13B is side view of the breakover assembly of FIG. 13A in anintermediate pivoted position;

FIG. 13C is a side view of the breakover assembly of FIG. 13A in afullyforward pivoted position;

FIG. 14 is an exploded perspective view of a seat back breakoverassembly and a seat back;

FIG. 15 is a exploded perspective view of a meal tray assembly;

FIG. 16 is a perspective view of the meal tray assembly of FIG. 15;

FIG. 17 is an exploded perspective view of an alternative meal trayassembly;

FIG. 18 is a perspective view of the meal tray assembly of FIG. 17 in anopen position; and

FIG. 19 is a perspective view of the meal tray assembly of FIG. 17 in aclose position.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE SEAT ASSEMBLYOVERVIEW

Referring now specifically to the drawings, an aircraft passenger seatset according to the present invention is illustrated in FIGS. 1, 2 and3 and shown generally at reference numeral 10. In the particularembodiment shown in FIGS. 1, 2 and 3, the seat set 10 is comprised ofthree adjacent seats, an aisle seat 11, a center seat 12 and a windowseat 13. The seat set 10 is supported on a pair of leg modules 14 and15, and includes a baggage guard rail 16. The seats 11,12 and 13 areprovided with arm rests 18, 19, 20 and 21. The seats 11,12 and 13include seat bottoms 22, 23 and 24, respectively, and seat backs 25, 26and 27, respectively.

The internal structure of the seat set is shown in FIG. 4, with variousparts eliminated for clarity. As is shown, the seat set 10 is supportedon and thus shares the two leg modules 14 and 15. The leg modules 14 and15 carry a set of four laterally-extending beam elements 35, 36, 37 and38 on which are mounted four section assembly modules 40, 41, 42 and 43.The leg modules 14, 15; beam elements 35, 36, 37 and 38; and the sectionassembly modules 40, 41, 42 and 43 tie together the components in amanner necessary to form a seat set 10 having significant structuralintegrity within passenger comfort, fuselage size and governmentregulation requirements. The underlying structure 94 defined by legmodules 14, 15; beam elements 35, 36, 37 and 38; and the sectionassembly modules 40, 41, 42 and 43 is referred to as a “ladder frameassembly” and is indicated at reference numeral 50 in FIGS. 4 and 5. Theladder frame assembly 50 carries seat back pans 26A, 27A, see FIG. 4,and seat back pan 25A, see FIG. 5.

Of course, the seats according to the present invention can beintegrated together to form seat sets of different lengths, spacings,and numbers of seats. Whether one, two, three or more seats, each seatset 10 will include at least two leg modules, such as leg modules 14 and15. Thus, when a seat is referred to as having a pair or a plurality ofleg modules, it is understood that at least two leg modules arerequired, but that the two leg modules may not necessarily be onopposing sides of any particular seat. For example, in FIGS. 1-5, threeseats 11,12 and 13 are each supported on two leg modules 14,15. Thus,seat 11 is supported on two leg modules 14,15, just as are seats 12 and,13, and whether the seat set 10 is considered a “seat” or the threeseats 11, 12 and 13 are considered “seats”, in either case they aresupported by a plurality of legs.

Low Profile Seat Back Recline Locking Assembly

Referring now to FIGS. 6 and 7, a low profile seat back recline lockingassembly is shown. A hydraulic cylinder 60 interconnects the sectionassembly module 41 and the seat back pan 25A. A control button, notshown, on the arm rest 19 can be depressed by the seat occupant to varythe recline angle of the seat back 26 relative to the seat bottom 23.The control button is connected to a control cable, not shown, whichconnects to the actuator 61 residing on top of the cylinder 60. When thecontrol button is depressed, the actuator 61 unlocks the cylinder 60.Backward pressure on the seat back pan 25A allows the seat back pan 25Ato recline. Release of back pressure on the seat back pan 25A by theseat occupant allows the seat back pan 25A to move forwardly to a moreupright position. Release of the control button locks the seat back 25in the current position.

The cylinder 60 is mounted for pivotal movement to the section assemblymodule by an offset pivot shaft 62 by a lower cylinder pivot bushing 63and to the seat back pan 25A by a pair of upper cylinder pivot bushings64, 65 between which fits a pivot bushing, not shown, residing behindthe lower extent of the seat back pan 25A. The upper cylinder pivotbushings 64, 65 are locked in place by a lock pin 68, designed to beremovable without tools.

The pivot shaft 62 is locked to the section assembly module 41 by apear-shaped spacer collar 70 having a bore 71 into which the pivot shaft62 extends. The spacer collar 70 is connected to the section assemblymodule 41 by a screw 72 which is threaded into a matingly threaded screwhole 73 in the small end of the spacer collar 70.

Note that the spacer collar 70 fits against a stepped surface portion ofthe section assembly module 41. The stepped surface portion includes afirst portion 75 which is flush with the surrounding surface of thesection assembly module 41 and a second portion 76 which is recessedbelow the surrounding surface of the section assembly module 41. Thepivot shaft fits into a bore 78 in the section assembly module 41, andthe screw 72 threads into a matingly threaded hole 79.

Thus, in order to lock the pivot shaft 62 against movement relative tothe section assembly module 41, the screw 72 is tightened to the pointwhere the smaller end of the spacer collar 70 is drawn inwardly into therecessed portion 76 of the section assembly module underlying the spacercollar 70. This tilting movement creates a misalignment of the axis ofthe spacer collar 70 relative to the axis of the pivot shaft 62, thuslocking the pivot shaft 62 against both axial and rotational movementrelative to the section assembly module 41. As the seat back pan 25Amoves, the cylinder 60 pivots about the pivot shaft 62.

Similarly, the seat back pivot shaft 80 is mounted in a pivot bushing 81on the seat back pan 25A and in a bore 82 in the section assembly module41. The seat back pivot shaft 80 is locked to the section assemblymodule 41 by a spacer collar 84. In the same manner as described above,the spacer collar 84 sits over a stepped portion of the surface of thesection assembly module 41, so that when the screw 85 is tightened, thesmall end of the spacer collar 84 is misaligned, locking the seat backpivot shaft 80 in a fixed position relative to the section assemblymodule 41.

The spacer collars 70 and 84 are preferably manufactured from extrusionand thus can be easily made in any desired thickness.

The seat back pivot shaft 80 is attached to the pivot bushing by afastener 87. A screw 88 is threaded into the fastener 87, which includesa misaligned portion 89. As the screw 88 is tightened, the misalignedportion 89 becomes progressively more misaligned, securing the seat backpivot shaft 80 to the pivot bushing 81 of the seat back pan 25A.

As is shown in FIG. 7, beam elements 35 and 36 carry the sectionassembly module 41, also as shown in FIG. 4, together with the beamelements 37 and 38.

The cylinder 60 is very compact—approximately 5 inches betweenattachment points, and has a ½ inch stoke. By locating the actuator 61astride the cylinder 60, the overall length is further reduced. Thisshorter length allows the cylinder 60 to be located in a nearly verticalposition to one side of and behind the seat occupant. The seat bottompan therefore has a clean appearance without local protuberances. As aresult, the bottom cushion can be thinner, less complex, morecomfortable and lighter than those in current use. Recline of the seatback 26 is unaffected, and is completely transparent to the seatoccupant.

Seat Frame Construction

Referring now to FIG. 8, leg module 14 is described in further detail.Leg module 14 includes a rear floor track fitting 90 by which the seatset 10 is attached to a track extending along the fuselage deck fromfront to rear, a floor tie assembly 91, a front leg 92, a front trackfitting 93, and a diagonal leg tie 94. A pair of joint clamps 96, 98 areprovided and comprise an annular collar element 96A, 98A, respectively,which receive the beam elements 37, 36, and attachment elements 96B,98B, respectively, by which the joint clamps 96, 98 are attached to theleg module 14.

The joint clamps 96, 98 are secured by screws 99 to the top of the frontleg 92 and the diagonal leg tie 94, respectively. The joint clamps 96,98 include axially-extending splits 96C, 98C, respectively, which permitthe collar elements 96B, 98B to be spread sufficiently to permitinsertion of the beam elements 37,36. Screws 100 permit the collarelements 96B, 98B to be tightened for locking the beam elements 37, 36in place in a predetermined position, and loosened for permitting thebeam elements 37, 36 to the removed from or shifted axially within thecollar elements 96B, 98B.

As shown in FIG. 4, the section assembly modules 41 and 42 are mountedto the beam elements 37, 36 in an offset position relative to the jointclamps 96, 98 and form the ladder frame assembly 50.

Referring now to FIGS. 9,10 and 11, the manner in which the joint clamps96, 98 may be used to vary seat spacing is illustrated. As noted above,spacing between parallel sets of floor tracks is generally fixed, sothat the need to have seats with varying spacing in prior artconstructions has been accommodated by having differently-constructedleg modules with various offsets to the left or right of the centerlineof the leg module. By using the joint clamps 96, 98, seat spacing isvaried using the same components, avoiding the need to have a number ofdifferently-constructed leg modules and components. For example, in FIG.9 the joint clamps 96, 98 are positioned on the right side of the legmodules 14, 15. The location of the collars 96A, 98A permit the sectionassembly modules 41, 42 to be positioned in vertical alignment with orto the left of the leg modules 14,15.

In FIG. 10 the joint clamps 96, 98 are positioned on the left side ofthe leg modules 14, 15, permitting the section assembly modules 41, 42to be positioned in vertical alignment with or to the right of the legmodules 14,15.

In FIG. 11 the joint clamps 96, 98 are positioned inboard of the legmodules 14, 15, permitting the section assembly modules 41, 42 to bepositioned in vertical alignment with or outboard of the leg modules14,15. Even though not shown, it is also apparent that the joint clampscan be both positioned outboard of the leg modules 14,15, permitting thesection assembly modules 41, 42 to be positioned in vertical alignmentwith or inboard of the leg modules 14, 15. The attachments are notpermanent, so that modifications to the seat spacing requirements can bequickly and easily accomplished.

Seat Back Breakover Assembly

Referring now to FIGS. 12,13, 13A-C and 14, a breakover assembly 100 fora passenger seat such as the passenger seat 11 is shown. The breakoverassembly 100 is intended to normally prevent the seat back 25, see FIG.5, from pivoting forward past an upright position towards the seatbottom 22, while allowing this movement if struck with a sufficientlyhard forwardly-directed force, such as might occur if hit from the rearby an occupant seated directly behind the seat. The purpose of thebreakover assembly 100 is to prevent damage to the seat 11 resultingfrom a severe rear impact and to at least reduce injury to an occupantthrown against the rear of the seat back by allowing the seat back tomove forwardly in a controlled manner.

In general, this is effected by utilizing a bent steel wire to resistimpact up to a certain predetermined load, and then absorb the energy byforcing the bend in the wire rearwardly relative to the wire, forwardlyrelative to the seat, and giving off excess energy in the form of heat.

Specifically, a bent steel wire 101 as is shown in the simplified viewof FIG. 12 is captured by a retainer bracket 102. The steel wire is a0.235 inch 1018 grade wire. An energy-absorbing roller 103 and bushing103A are positioned inside the bend of the steel wire 101. The roller103 is captured in holes 105A and 106A in back supports 105,106,respectively and thus must move in unison with the back supports105,106. The bushing 103A resides in lateral alignment with the steelwire 101 inside the bend.

A shear pin 104 carrying a shear bushing 104A thereon is captured inholes 105B and 106B in back supports 105, 105, respectively. The shearbushing 104A is captured in an annular recess 107 in a quadrant member108. The steel wire 101 fits around the back side 108 of the quadrantmember 108, with the forward portion of the wire 101 positioned in theelongate slot 109. The forward portion of the wire 101 is retained inslot 109 by an enlarged head 1 01A which fits within an annular recessat the end of the slot 109. See FIG. 13.

The entire seat back 25 pivots on the pivot bushing 112 on which theback supports 105,106 and quadrant 108 are positioned. See FIG. 14.Other components shown are illustrated and described above.

In operation, an abnormal force, for example, the impact of a passengeron the rear of the seat during a 16 g event will cause the seat back 25to move forward while the quadrant 108 remains stationary. The shearbushing 104A fits snugly within the recess 107 and thus quickly breaks.The shear bushing 104A is designed to break upon impact of between180-220 pounds on the top of the seat back 25. See FIGS. 13A, 13B. Thewidth of the shear bushing 104A can be varied, and in doing so theamount of force required to break the shear bushing 104A can be varied.The wire 101 is protected from any load until the shear bushing 104Abreaks.

As the shear bushing 104A breaks, the seat back 25 continues forward,bringing the bushing 103A up against the back of the inside of the bendin the wire 101. As the seat back 25 continues forward, the bushing 103Acontinues forward, and the wire 101 is pulled around the bushing 103A,moving the position of the bend. See FIG. 13C. Energy is absorbed in twoways, movement of the position of the bend along the length of the wire101 and heat released as the wire 101 thus bent.

Wire 101 is designed to begin movement at 150 pounds of force, andpermits the seat back 25 to move through a maximum arc of 70 degrees.The combined use of the sacrificial bushing 104A and the wire 101controls the movement of the seat back 25 in such a manner thatsurvivability of the passenger is improved at an impact force as low as1G. The seat back 25 can be returned to its normal position by pushingit rearward using less than a 35 lbs force.

When the seat back must be moved forward for maintenance or cleaning,the lock pin 68 may be removed, disconnecting the hydraulic seat reclinecylinder 60 from the retainer bracket 102 and the seat back 25. In thisconfiguration the seat back 25 may be moved forward to the breakoverposition without interfering with the quadrant 108.

Meal Tray Assembly—Preferred Embodiment

Referring now to FIG. 15, a meal tray assembly 120 according a preferredembodiment of the invention is illustrated. The meal tray assemblyincludes a pair of laterally spaced-apart latch plates 121, 122connected to the back surface of the seat back pan 25A of passenger seat11 directly above a meal tray stowage position. The latch plates 121,122include inwardly-facing pin retention recesses 121A, 122A, respectively.The dress cover of the seat back 25 is around the latch plates 121, 122so as not to interfere with the latch plates 121, 122 when the dresscover is removed for cleaning or replacement.

A cross-member 124 is positioned laterally across the surface of theseat back pan 25A and releasably locked to the seat back pan 25A by apair of locking pins 125,126, which are mounted in recesses, not shown,in the back side of the cross-member 124 by a pair of cover plates 128,129. The cross-member 124 is positioned over the dress cover. Thelocking pins 125,126 are biased in the locked position by springs 131,132. When the cross-member 124 is placed against the back of the seatback pan 25A and over the latch plates 121, 122, the locking pins 125,126 extend into the retention recesses 121A, 122A and lock thecross-member 124 to the back of the seat back pan 25A.

The cross-member 124 is contoured to define a central recess 135. Arotatable “barn door” latching member 137 is positioned within therecess 135 and is movable between an extended position with the latchingmember 137 extending downwardly from the cross-member 124 intointerfering relation with a top edge 139 of a meal tray 140, and aretracted position with the latching member 137 extending laterally toone side within the recess 135 in non-interfering relation with the topedge 139 of the meal tray 140. The meal tray 140 also includes a recess141 which communicates with the top edge 139 of the meal tray 140. Therecess 135 in the cross-member 124 and the recess 141 in the meal tray140 collectively form a recess within which the latching member 137resides, and thus prevents inadvertent impact from passing passengerswhich could cause deployment of the meal tray 140.

The locking pins 125,126 are manually operable by downwardly-extendingfingers 125A, 126 from the lower side of the cross-member 124 when themeal tray 140 is in its deployed position.

Installation is accomplished without tools. Repairs and part replacementmay be made without tools and without removing the dress cover from theseat back 25.

Meal Tray Assembly-Alternative Embodiment

Referring now to FIGS. 17,18 and 19, an alternative embodiment meal trayassembly 150 is shown. A meal tray 151 is mounted for movement between astowage position flush against the back side of a seat back pan 25A,FIG. 19, and a lowered, horizontal use position, FIG. 18. An elongatelatch access port 153 extends through the meal tray 151 near its topedge. Note that the latch access port is “subflush” to the bottomsurface of the meal tray 151, and is surrounded by a recess 154.

A latch mounting plate 155 is secured to the back side of the seat backpan 25A, to which is mounted an annular detent plate 157. Detent plate157 includes four 90 degree detent dimples 157A molded into the face. Anelongate latch 160 is carried by the detent plate 157 by a pin assembly158 and is rotatable between a release position, shown in FIG. 18, wherethe elongate latch 160 may be aligned with and extended through theelongate latch access port 153 for permitting movement of the meal tray151 to and from the stowage position and the use position. When the mealtray 151 has been moved to the stowage position with the latch 160extending though the latch access port 153, the latch 160 is rotated ineither the clockwise or counterclockwise direction 90 degrees. The latch160 overlaps the edge of the latch access port 153 and is caught on theedge of the meal tray 151 surrounding the latch access port 153, lockingthe meal tray 151 in the stowage position.

To release the meal tray 151 and allow it to be moved to the useposition, the latch 160 is rotated a further 90 degrees in eitherdirection and into alignment with the lengthwise axis of the latchaccess port 153. In this position, the meal tray 151 may be lowered pastthe latch 160 and into the use position.

Because the latch 160 captures the meal tray 151 through the latchaccess port 153, inadvertent disengagement of the meal tray 151 by forceapplied in any direction is prevented, in contrast with current “barndoor” latches. In addition, the recess 154 around the latch access port153 prevents inadvertent rotation of the latch 160 and deployment of themeal tray 151 to the use position, as might otherwise occur when apassenger brushes against the tray while moving to or from his or herown seat.

A passenger seat, passenger seat leg module and a method of constructinga passenger seat are described above. Various details of the inventionmay be changed without departing from its scope. Furthermore, theforegoing description of the preferred embodiment of the invention andthe best mode for practicing the invention are provided for the purposeof illustration only and not for the purpose of limitation—the inventionbeing defined by the claims.

I claim:
 1. A passenger seat, comprising: (a) a seat bottom chassisincluding a plurality of leg modules, said leg modules for beingattached to fixed, spaced-apart attachment points on a supportingsurface; (b) a plurality of beam elements for being carried by said legmodules; (c) a plurality of clamp joints for being positioned on a firstside of said leg modules in a first laterally-offset relation thereto ina first spaced-apart relation to the attachment points of the supportingsurface and for receiving the plurality of beam elements for defining aladder frame assembly having a first specified width and seat spacing;and (d) said plurality of clamp joints being removable from the firstside of said leg modules and positioned on a second, opposite side ofsaid leg modules in a second laterally-offset relation thereto fordefining a ladder frame assembly having a second specified width andseat spacing while the plurality of leg modules maintain the sameposition relative to each other and thus to the fixed, spaced apartattachment points whereby the location of the seats may be altered whileusing the same beam elements.
 2. A passenger seat according to claim 1,and including a seat back recline assembly, comprising: (a) a pluralityof seat section assembly modules carried by said leg modules, and a seatback unit pivotally-mounted between two of the section assembly modulesfor permitting the angle of the seat back relative to the seat bottomchassis to be varied as desired by the passenger; and (b) a recline unitfor controlling movement of the seat back and locking the seat back in adesired recline position.
 3. A passenger seat according to claim 1,wherein each of said leg modules comprises: (a) a rear foot block andfloor tie assembly; (b) a front leg: (c) a diagonal leg tie connectingthe rear foot block and the front leg; (d) wherein a first one of theplurality of clamp joints is connected in laterally-offset relation toone side of the diagonal leg tie intermediate the rear foot block andthe front leg; and (e) wherein a second one of the plurality of clampjoints is connected in laterally offset relation to one side of thefront leg.
 4. A passenger seat according to claim 1 or 3, wherein saidclamp joint comprises an attachment element for being attached to theleg module and an annular collar element for receiving a beamtherethrough.
 5. A passenger seat according to claim 4, wherein saidclamp joint attachment element includes holes therein for receivingattachment bolts therethrough and through mating holes in the legmodule.
 6. A passenger seat according to claim 4, wherein said clampjoint collar includes: (a) an axially-extending split therein forallowing the collar to be spread sufficiently to receive the beamtherethrough; and (b) a threaded fastener adjustably connecting thecollar on opposite sides of the split for permitting the collar to betightened for locking the beam in place within the collar in apredetermined position and loosened for permitting the beam to theremoved from or shifted axially within the collar.
 7. A passenger seataccording to claim 1, wherein said passenger seat includes first andsecond spaced-apart leg modules and further wherein: (a) the clampjoints of the first leg module are positioned on a left side thereof;and (b) the clamp joints of the second leg module are positioned on aright side thereof.
 8. A passenger seat according to claim 1, whereinsaid passenger seat includes first and second spaced-apart leg modulesand further wherein: (a) the clamp joints of the first leg module arepositioned on a right side thereof; and (b) the clamp joints of thesecond leg module are positioned on a right side thereof.
 9. A passengerseat according to claim 1, wherein said passenger seat includes firstand second spaced-apart leg modules and further wherein: (a) the clampjoints of the first leg module are positioned on a left side thereof;and (b) the clamp joints of the second leg module are positioned on aleft side thereof.
 10. A passenger seat leg module, comprising: (a) arear foot block and floor tie assembly; (b) a front leg; (c) a diagonalleg tie connecting the rear foot block and the front leg; (d) a firstclamp joint attached in laterally-offset relation to a selected one of aleft or right side of the diagonal leg tie intermediate the rear footblock and the front leg; and (e) a second clamp joint attached inlaterally-offset relation to a selected one of a left or right side ofthe front leg for receiving a beam therethrough, wherein each of saidclamp joints comprises an attachment element connected to the lea moduleand an annular collar element which protrudes above the top of said legmodule for receiving a beam which extends laterally through said collarelement and contiously spans at least two of said leg modules.
 11. Apassenger seat leg module according to claim 10, wherein said clampjoint attachment element includes holes therein for receiving attachmentbolts therethrough and through mating holes in the leg module.
 12. Apassenger seat leg module according to claim 11, wherein said clampjoint collar includes: (a) an axially-extending split therein forallowing the collar to be spread sufficiently to receive the beamtherethrough; and (b) a threaded fastener adjustably connecting thecollar on opposite sides of the split for permitting the collar to betightened for locking the beam in place within the collar in apredetermined position and loosened for permitting the beam to be tremoved from or shifted axially within the collar.
 13. A method ofmounting a passenger seat to attachment points on a supporting surface,comprising the steps of: (a) providing: (i) a seat bottom chassisincluding a plurality of leg modules, said leg modules for beingattached to fixed, laterally spaced-apart attachment points on asupporting surface; (ii) a plurality of laterally-extending beamelements for being carried by said leg modules; (iii) a plurality ofclamp joints; (b) attaching a clamp joint to a selected left or rightlateral side of each of said leg modules for clamping the plurality ofleg modules together in spaced-apart relation to each other, each saidclamp joint having an attachment element connected to said leg moduleand an annular collar element which protrudes above the top o said legmodule for receiving a laterally-extending beam therethrough; and (c)extending the plurality of beam elements through said annular collarelements in said clamp joints for defining a ladder frame assemblyhaving a predetermined width and seat spacing, wherein each of saidbeams continuously spans at least two of said leg modules.
 14. A methodaccording to claim 13, and including the steps of: (a) removing thebeams from the clamp joints; (b) removing the clamp joints from one sideof the leg modules and attaching the clamp joints to an opposite side ofthe leg modules; (c) extending the plurality of beam elements throughrespective openings in the clamp joints to define a ladder frameassembly having a second specified width and seat spacing.
 15. A methodaccording to claim 14 and including the steps of: (a) positioning theclamp joints of a first leg module on a left side thereof; and (b)positioning the clamp joints of a second leg module on a right sidethereof.
 16. A method according to claim 14 and including the steps of:(a) positioning the clamp joints of a first leg module on a right sidethereof; and (b) positioning the clamp joints of a second leg module ona right side thereof.
 17. A method according to claim 14 and includingthe steps of: (a) positioning the clamp joints of a first leg module ona left side thereof; and (b) positioning the clamp joints of a secondleg module on a left side thereof.